Biomedical subjects

Suresh Bhat

Publications and source records attributed to Suresh Bhat.

4 recordsLinked to original sources

PubMed2006

Multiple-scattering suppression in dynamic light scattering based on a digital camera detection scheme.

We introduce a charge-coupled device (CCD) camera-based detection scheme in dynamic light scattering that provides information on the single-scattered autocorrelation function even for fairly turbid samples. It is based on the single focused laser beam geometry combined with the selective cross-correlation analysis of the scattered light intensity. Using a CCD camera as a multispeckle detector, we show how spatial correlations in the intensity pattern can be linked to single- and multiple-scattering processes. Multiple-scattering suppression is then achieved by an efficient cross-correlation algorithm working in real time with a temporal resolution down to 0.02 s. Our approach allows access to the extensive range of systems that show low-order scattering by selective detection of the singly scattered light. Model experiments on slowly relaxing suspensions of titanium dioxide in glycerol were carried out to establish the validity range of our approach. Successful application of the method is demonstrated up to a scattering coefficient of more than micro(S) = 5 cm(-1) for the sample size of L = 1 cm.

Complex Mixtures↗

PubMed2006

Virtual cystoscopy by intravesical instillation of dilute contrast medium: preliminary experience.

PURPOSE: We determined whether virtual cystoscopy based on helical data sets can yield urinary capabilities similar to those achieved by fiber-optic cystoscopy. MATERIALS AND METHODS: A total of 11 patients with ultrasound detected bladder tumors underwent pelvic CT as a single volumetric scan after preliminary bladder distention with saline mixed with contrast medium using a 6Fr infant feeding tube. Cystoscopy was simulated based on a 3-dimensional helical CT data set in real time. Source raw CT data for virtual cystoscopy were reconstructed and navigation was done in real time using surface rendering navigation software. These images and findings were then compared with conventional cystoscopy findings. RESULTS: An attenuation gradient of 350 HU between the vesical mucosa and urine was noted. Two of the 14 tumors (11 patients) were missed and each was 0.7 cm. All tumors greater than 0.9 cm were detected. Overall sensitivity was 85.7%. There were no false-positive findings. There was good correlation with tumor location and size. The ureteral orifices and their relationship to the tumor were also well appreciated. Subtle mucosal changes on conventional cystoscopy were not delineated by virtual cystoscopy. CONCLUSIONS: Our method of instilling dilute contrast medium in the bladder offers an excellent attenuation gradient. The overall sensitivity of tumor detection is better than that reported for intravenous contrast medium and pneumocystoscopy.

Administration, Intravesical↗

PubMed2005

Colour Doppler ultrasonographic location of the bulbourethral artery, and its impact on surgical outcome.

OBJECTIVE: To assess the location of bulbourethral arteries in men with a 'normal' urethra and to study anatomical alterations in men with urethral stricture. PATIENTS AND METHODS: A linear-array transducer was used on the ventral surface of the penis to study the urethra. Fifteen men with a normal urethra and 15 with a stricture of the bulbar urethra were assessed. After conventional grey-scale imaging to evaluate the extent of disease, the urethral artery in the bulbar urethra was located by colour Doppler ultrasonography. RESULTS: The site of the urethral arteries in 'normal' men varied among individuals; they were at the 10-2 o'clock position in six men, 8-10 o'clock and 2-4 o'clock in six, and at the 4-8 o'clock position in three. In normal men the symmetry of arteries was maintained and the mean distance from the lumen was 2.67 mm. In men with urethral stricture, there was a loss of symmetry in all cases. In a dense stricture the urethral arteries could not be detected on either side in three of cases, while only a single artery was seen in three. In two men, both the arteries were on one side. The mean distance of the urethral artery from the lumen of urethra was 1.88 mm. CONCLUSIONS: Contrary to the popular belief that the urethral arteries are located at the 3 and 9 o'clock position, we found that there was no predictable pattern for their anatomy. These observations might have implications for treating urethral stricture disease with visual internal urethrotomy, as they could help to avoid injury to the bulbourethral artery.

Adult↗

PubMed2004

Youssef's syndrome--report of 7 cases and review of literature.

Seven patients in their thirties presented with cyclical haematuria, apparent amenorrhoea and urinary continence following lower segment caesarean section. Investigations confirmed the diagnosis of Youssef's syndrome. Four patients who had 2 children each opted for hysterectomy. The remaining 3 patients had excision of the fistula with repair of uterus and bladder. In this group, at 6 years follow-up, in spite of conceiving, 2 patients aborted with no further pregnancy reported.

Amenorrhea↗